Filter construction and method of filtering



July 20, 1943.

E. HQCARRUTHERS ET AL FILTER CONSTRUCTION AND METHOD OF FILTEEKING Filed Au 14, 1940 INVENTORS Mar fir: n8 J 17315-070 moors loosening the nuts ll Patented July 20, 1943 FILTER CONSTRUCTION METHOD OF FILTERING Eben Hunter Carruthers. Astoria,

Henry Tyson Moore, Drexel Hill, Pm, assignors, by mesne assignments, to The Sharples Corporation, Philadelphia, Pa., a corporation of Delaware Application August 14, 1940, Serial No. 352,560 3 Claims. (Cl. 210-137) The present invention relates to filters and to a method of filtering.

An object of the invention is to provide a generally improved and simplified filter construction which may be built at a reasonable cost and which is extremely convenient and economical to operate.

Another object of the invention is the provision of a filter which may be charged with filtering material and made ready for operation with a minimum of physical efi'ort, and from which the spentfiltering material may be readily discharged, and the spent filtering material quickly replaced with fresh filtering medium.

The. invention further contemplates a method oi filtering or a method of operating a filter so as to economize on the Other objects and advantages-o1 the invention will be particularly pointed out in the claims and will be apparent from the followingdescriptlon, when taken in connection with the accompanying drawing, in which:

Fig. 1' is a side elevation ofthe filter;

Fig. 2 is a sectional view of the filter;

Fig. 3 is a view of one side of one form of grid which may be used in'the filter;

Fig. 4 is a view of the other side thereof; and

Fig. 5 is a sectional viewof the grid.

The filter and method of filtering of our invention may, in general, be employed in any filtering process wherein impurities areto be removed from a liquid by flowing the liquid through a bed of filtering material. The filtering material may be Jfullers earth, clay, sand, or other suitable filtering media. The filter and method of filtering of our invention may, for example, be employed in connection with the purification process shown anddescribed in the copendlng application of Eben H. Carruthers, Serial No. 330,146, filed April 17, 1940, entitled Method and apparaius for oil purification.

The filtering apparatus, in general, comprises dimensions, and shape, drawing a cylindrical drum having open ends end of the drum uppermost. Preferably the drum is pivoted substantially along its center of gravity so that it may be manually inverted.

While thedrum may be of any suitable-size,

there is shown in the which may be provided with flanges or rings 2| welded to the ends of the side walls. The open ends of the drum are closed by flanged covers or head plates 2! and 22, which are preferably domeshaped so as to provide a compartment or well at each end of the drum.

Since the construction of both head plates is the same, a descriptionoi one will suiiice. The

use of filtering material.

a base I I. and a pair of preferably channel-shaped pedestals l2 which extend upward from the base.

The upper ends of the pedestals are provided, with saddles l3 for thereception of pivots, generally indicated by the numeral I, mounted on the sides of a container or drum ii for the filtering medium. As shown in the drawing, the upper ends of the pedestals are slotted at II for the recepthreaded to receive nuts 18. Washers I! are provided between the pedestals and the nuts II. By the container or drum may be pivoted in the'saddles it so as to bring either ton of the pivots and the ends of the pivots are head. plate -22"may be provided with handles 23 by which it may be conveniently removed and replaced, and the fianges thereof may be bolted to the flanges 2i by nuts (Fig. 1). As shownin the drawing, the head plate 22 is provided with a conduit 26 which is threaded at its outer end for the reception of a pipe and which extends through the wall oi the head plate and terminates adjacent the center and closely adjacent the inner wall of thehead plate} as shown at 21. The inner surface of the head plate may be provided with ribs 28 which may be welded to the wall of the head plate and which are for a purpose which will later appear. J

Approximately at the horizontal center of the drum is located a dividing wall 29 which separates the interior of the drum intotwo filterbed sectlons, ti and 32. The dividing wall may be welded in position and may be provided with a series of apertures to permit the flow of liquid from one section to the other. In the drawing, to insure rather thorough comingling oi the liquid after it has passed through tion against any substantial. migration with the liquid being filtered. Any suitable filtering pad may be. employed. It is desirable, in filtering most liquids, that the filtering pad oirer as little resistance to flow of the liquid as possible, and we have found ordinary burlap to be suitable for this P rpose. a

The filtering pads I! are held in position by sealing rings. Each oi the sealing rings comone filter bed and before it passes to the next, there is shown only a prises an annular channel-shaped member 3! in the channel of which is held a sealing material 4 I. The sealing material may be felt. rubber, or such other suitable material as will, when pressed against the inner side walls of the drum, form a tight seal thereagainst to prevent the liquid being filtered from flowing past the sealingring. The top and bottom of the drum are each provided with a filter pad H, a sealing ring 3, and a grid 44. Each of these elements may be similar in construction to the corresponding elements, adjacent the dividing wall, above described. Each of the grids is supported and held in position against the weight of the filtering material by the ribbing 28, the weight of the filtering material being applied to the particular grid which happens to be lowermost.

Supported by the base I l is a container or pan 4! which lies beneath the drum and is adapted to receive spent filtering material when the drum,

The grid 36 is reversely arranged and tends to uniformly distribute the liquid over the upper is emptied. The pan may be of any suitable size,

shape. and construction, and may be provided with a handle 41 to enable removal of the pan.

Any suitable type of grid may beemployed. For example, the grid might be a plain apertured disk, such as would support the filtering material and yet permit free fiow of the liquid therethrough. However, for maximum filtering em: ciency, we have found that it is preferable that the grid serve to substantially uniformly distribute the liquid over the area of the filter bed as, for example, over the top surface of the upper filter bed it (as shown in Fig. 2).

For this purpose one surface of the grid, as shown in Fig. 3, is provided with an annular groove 5| which communicates with channels 52 surface of the lower filter bed in the same manner as described above in connection with the grid M. The lowermost grid is arranged similarly to the grid 44 with the ribbed surfaces facing each other so that when the lower filter section is uppermost it will serve the same function as the upper grid 44. After. passing through the lower filter bed and out through the apertures in the lower grid, the liquid drops into the well, formed by the lower head plate 20, and may be withdrawn from the lower head by a suitable suction pump (not shown). It will be noted that the end 21 of the conduit is adjacent the wall of the head plate and the lowest point of the well so that substantially all of the liquid may be sucked from the well formed by the head plate.

The filter sections 3i and 32 are filled with any suitable filtering material, such as fuller's earth,

in a manner which will be readily apparent. Either of the head plates is removed and either filter section filled with filtering material, the parts replaced and the head bolted in position.

The filter is then rotated and the other filter formed between ribs 03. The ribs and channels may be located as desired in the surface of the grid, but preferably extend parallel to each other. The liquid fiows along the channels and substantlally evenly distributes itself over the grid surface. Any desired number of apertures 84 may be employed and arranged as desired, but preferably arranged so that they communicate with the channels and are substantially uniformly distributed over the grid surface.

The opposite side of the grid has a rim 5! and an arinular baille 51 forming an inner section 58 and an outer section 59. The bail'le 81 has gate- .ways 61 which connect the inner and outer sec-" tions 58 and B8.

The grids are mounted in position, as shown in the drawing, the top grid as viewed in Fig. 2 being arranged with the ribbed surface lowermost so that when liquid to be filtered is supplied through the conduit 21, it drops (assuming a gravity now of the liquid through the filter) upon the grid and distributes itself over the surface thereof. After flowing through the apertures 54, it reaches the ribbed side of the grid and tends to flow along the channels and substantially evenly distribute itself over the top area of the filter bed.

After fiowing through the upper filter section ll, it reaches the grid 14 which is arranged with its ribbed surface uppermost. The liquid then flows along the channels until it reaches the apertures 54 and fiows to the under side of the grid 84. The under side of the grid 34, together with the dividing wall 29, then acts as a collector and tends to mix the liquid and render it more or less homogeneous. The baflie ll acts as an obstruction so as to retard the flow and cause the liquid to become somewhat more thoroughly mixed besection is filled with filtering medium. In filtering some materials, such as lubricating oil, it is desirable to heat the liquid to a temperature of, for example, F. to 200 F. Preferably the oil is brought to this temperature before being passed through the filter.

While a gravity fiow of liquid may be employed in the filter, it is preferable that the liquid be forced and drawn through the filter sections in series by pressure applied through the upper conduit and suction through the lower conduit. It is desirable that both pressure and suction be employed although either suction or pressure may be used alone. Thus the liquid is forced and drawn -rather rapidly through the filter. The flow through the filter, if gravity alone is employed, is rather slow. when pressure is employed, of course, the upper head plate will be flooded with liquid so that the pressure thereof is exerted on the grid so as to force the liquid through the grid apertures and through the filtering medium.

After the filter has been in operation for some time the clay or other filtering material loses its ability toextract impurities from the liquid being filtered. In the case of purification of engine lubricating oil,-the fact that the filtering medium has been spent can be ascertained by observing the character of the oil as it leaves the filter. When it is desired to change the filtering material, since the upper filter bed does most of the work, the material therein becomes spent first. After the conduits 28 have been disconnected the drum is rotated to bring the filtering bed ii to a lowered position so as to permit removal of the head plate 22, the grid, and the sealing ring 43, and thus permit the filtering material to drop by gravity into the pan 46.

When the filter section II is emptied the drum ent that various changes and modifications may I conduits 26, the filter may be placed in operation.

The length of time which the filtering material will last depends upon the character of the liq uid being filterer and other factors. Experience will determine how frequently the filtering mate-, rial should be replaced. As soon as the failure of the filter to clear up or remove impurities from the liquid is noted, the same procedure is followed in replacing the filtering material in the filter section 32 which is then in the uppermost position. In operating the system the fresh filtering bed is always the second bed of the series with respect to the entering liquid.

The method of operating the filter, as above described, results in a considerable saving in clay or other filtering medium, since the partly spent clay is always the first bed of the series through which the liquid flows so that the clay may be completely spent before it is removed and replaced.

While we have described the filter as being operated so that the liquid flows downward through the filter, it willbe appreciated that if pressure is employed with suction applied through the upper conduit, the liquid may be forced to flow upward or horizontally through the filter beds. The apparatus described is particularly convenient in enabling handling and servicing of the filter since the filter beds may be quickly emptied and their contents replaced. Preferably in ployed to force a larger percentage of the liquid out of the clay before the. clay isdiscarded.

- Moreover in draining the filter it is sometimes desirable that the liquid behot. Cold oil, for example, will not readily drain from the filtering material.

be made therein,- particularly in the form and relation of parts, without departing from the spirit of our invention as set forth in the ap- 1 pended claims.

We claim: 1. A method of filtering in which th filter has at least two filter beds and inlet and outlet While we have shown the preferred form of the filter of our invention, and described the preferred method of its operation, it will be apparconnections for the liquid to be filtered which comprises, arranging the filter beds and connections so that the liquid flows through the filter beds in series, replacing the filtering material in the first bed of said series with fresh filtering cmaterial when it becomes spent, and then rearranging the connections so that the liquid flows first througha filter bed in which the filtering material is partly used and later through a filterbed containing the fresh filtering material.

2. A filter structure comprising a container having ports connecting opposite ends thereof with a source of liquid supply and a liquid dis-, charge zone, respectively, a fixed partition 10- cated centrally between said inlet and discharge ports, said partition being perforated to permit passage of liquid therethrough, a pervious filter bed mounted between said partition and said feed port for removal through the end of the container to which it is adjacent, a second pervious filter bed mounted between said partition and said discharge port for removal through the end of the container to which it is adjacent, removably mounted means between each of said filter beds and the respective ends of said container for securing said filter beds in said ponent.

EBEN HUNTER CARRUTIIERJS. HENRY TYSON MOORE. 

